bookug
7/17/2017 - 1:46 PM
use Virtuoso's RESTful API to answer SPARQL queries in Java
use Virtuoso's RESTful API to answer SPARQL queries in Java
//REFERENCE:
//http://www.2cto.com/database/201405/298274.html
//http://docs.openlinksw.com/virtuoso/jdbcurl4mat/
//Problem: Number of licensed connections exceeded
//https://sourceforge.net/p/virtuoso/mailman/message/28445588/
//JDBC:
//http://vos.openlinksw.com/owiki/wiki/VOS/VOSDownload
import java.io.File;
import java.net.URLDecoder;
//DriverManager在java.sql这个包里面,管理一组 JDBC 驱动程序的基本服务
import java.sql.*;
import java.util.*;
public class Virtuoso {
public static Virtuoso instance = new Virtuoso();
//NOTICE: we do not use the cache because it will crash if the result's size is large
//Besides, FileUtil is not ok, we need to implement it.
//NOTICE: virtuoso has implemented a good query-level cache by itself, and we are not expected to do better
public boolean useCache = false;
Connection conn;
//String cacheFilePath = "resources/caches/virtuoso.cache";
//HashMap<String, List<String>> cache = new HashMap<String, List<String>>();
//HashMap<String, List<String>> updatedCache = new HashMap<String, List<String>>();
//public static int writeCacheThreshold = 10000;
public void connect()
{
try {
//加载想要连接的数据库的驱动到JVM（Java虚拟机）
Class.forName("virtuoso.jdbc4.Driver");
conn = DriverManager.getConnection("jdbc:virtuoso://0.0.0.0:1111/freebase","dba","dba");
/*
if( this.useCache )
this.loadCache();
*/
} catch (Exception e) {
e.printStackTrace();
}
}
public void close()
{
try{
if( conn != null ){
conn.close();
}
/*
if( this.useCache ){
List<String> outputs = writeCache();
FileUtil.writeFile(outputs, cacheFilePath, true);
}
*/
}catch(Exception e){
e.printStackTrace();
}
}
/*
public void flushCache()
{
List<String> outputs = writeCache();
FileUtil.writeFile(outputs, cacheFilePath, true);
this.updatedCache.clear();
}
public void loadCache(){
List<String> lines = new ArrayList<String>();
if( new File(cacheFilePath).exists() )
lines = FileUtil.readFile(cacheFilePath);
for(String line : lines){
String[] info = line.split("\t");
String key = info[0];
List<String> values = new ArrayList<String>();
for(int i = 1; i < info.length; i++)
values.add(info[i]);
this.cache.put(key, values);
}
}
public List<String> writeCache(){
List<String> lines = new ArrayList<String>();
for(String key : this.updatedCache.keySet() ){
StringBuffer buffer = new StringBuffer();
List<String> values = this.updatedCache.get(key);
buffer.append(key.replace("\t", " ").replace("\n", " ").trim() + "\t");
for(String value : values)
buffer.append(value+"\t");
lines.add( buffer.toString().trim() );
}
return lines;
}
*/
public Virtuoso(){
try {
this.connect();
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* An example of sparql: "sparql select * where { <fb:g.11vjx745d> ?y ?z}"
*/
public List<String> execute(String sparql)
{
/*
if( this.cache.containsKey(sparql.replace("\t", " ").replace("\n", " ").trim()) ){
return this.cache.get(sparql.replace("\t", " ").replace("\n", " ").trim());
}
*/
List<String> result = new ArrayList<String>();
try{
Statement stmt = conn.createStatement();
boolean more = stmt.execute(sparql);
ResultSetMetaData data = stmt.getResultSet().getMetaData();
while(more)
{
ResultSet rs = stmt.getResultSet();
while(rs.next())
{
StringBuffer s = new StringBuffer();
for(int i = 1;i <= data.getColumnCount();i++)
{
s.append(rs.getString(i) + "\t");
}
String sUTF8 = new String(s.toString().getBytes("ISO8859-1"),"UTF-8");
result.add(sUTF8.trim());
}
more = stmt.getMoreResults();
}
stmt.close();
/*
this.updatedCache.put(sparql, result);
if(this.useCache & this.updatedCache.size() > writeCacheThreshold)
flushCache();
*/
return result;
}catch(Exception e){
e.printStackTrace();
}
return null;
}
public List<String> executeFuzzyQuery(String sp){
List<String> names = new ArrayList<String>();
String subj = sp.split("\t")[0];
String pred = sp.split("\t")[1].trim();
try{
Set<String> result = new HashSet<String>();
for(String triple : this.execute("sparql select ?x where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> <"+pred.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?x .}")){
String mid = triple;
result.add(mid);
}
if( result.size() == 0 ){
List<String> triples = this.execute("sparql select ?x ?z where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?x ?y."
+ "?y <"+pred.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?z .}");
if( triples.size() > 60000 )
return names;
String newPred = new String();
for(String triple : triples){
String mid = triple.split("\t")[1];
newPred = triple.split("\t")[0].replace("http://rdf.freebase.com/ns/", "ns:")+".."+pred.replace("ns:", "");
result.add(mid);
}
names.add(newPred);
}
else
names.add(pred);
result.remove(subj.replace("ns:", "http://rdf.freebase.com/ns/"));
if( result.size() > 10000 )
return names;
for(String mid : result){
if( !mid.startsWith("http://rdf.freebase.com/ns/") ){
names.add("\""+URLDecoder.decode(new String(mid.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"")+"\"");
}
else{
for(String triple : this.execute("sparql select * where {<"+mid+"> <http://rdf.freebase.com/ns/type.object.name> ?z .}")){
names.add("\""+URLDecoder.decode(new String(triple.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"")+"\"");
}
}
}
return names;
}catch(Exception e){
}
return names;
}
@SuppressWarnings("finally")
public Set<String> executeSPQuery(String sp) {
Set<String> names = new HashSet<String>();
try {
Set<String> result = new HashSet<String>();
String subj = sp.split("\t")[0];
String pred = sp.split("\t")[1].trim();
if (pred.indexOf("..") != -1)
{
String firstPredicate = pred.split("\\.\\.")[0];
String secondPredicate = "ns:" + pred.split("\\.\\.")[1];
for (String triple : this
.execute("sparql select ?y where {<" + subj.replace("ns:", "http://rdf.freebase.com/ns/")
+ "> <" + firstPredicate.replace("ns:", "http://rdf.freebase.com/ns/") + "> ?x. "
+ "?x <" + secondPredicate.replace("ns:", "http://rdf.freebase.com/ns/") + "> ?y .}")) {
String mid = triple;
result.add(mid);
}
}
else
{
for (String triple : this
.execute("sparql select * where {<" + subj.replace("ns:", "http://rdf.freebase.com/ns/") + "> <"
+ pred.replace("ns:", "http://rdf.freebase.com/ns/") + "> ?z .}")) {
String mid = triple;
result.add(mid);
}
}
//Subject entity may occurred in answer set? Yes, <spouse>
result.remove(subj.replace("ns:", "http://rdf.freebase.com/ns/"));
if( result.size() > 500 )
return names;
//IDs should be translated to Names.
for (String mid : result)
{
if (!mid.startsWith("http://rdf.freebase.com/ns/"))
{
names.add(mid); //If json, maybe need : replace("\"", "\\\"")
//names.add("\"" + URLDecoder.decode(new String(mid.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"") + "\"");
}
else
{
for (String triple : this.execute("sparql select * where {<" + mid
+ "> <http://rdf.freebase.com/ns/type.object.name> ?z .}"))
{
names.add(triple); //If json, maybe need : replace("\"", "\\\"")
//names.add("\"" + URLDecoder.decode(new String(triple.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"") + "\"");
}
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
return names;
}
}
public Set<String> retrieveNeighbourNodes(String sp){
Set<String> results = new HashSet<String>();
String[] info = sp.split("\t");
String subj = "ns:"+info[0];
String pred = "ns:"+info[1];
if( pred.indexOf("..") == -1 )
return results;
String firstPred = pred.split("\\.\\.")[0];
List<String> triples = this.execute("sparql select ?z where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> <" + firstPred.replace("ns:", "http://rdf.freebase.com/ns/") + ">?x."
+ "?x ?y ?z .}");
for(String triple : triples){
if( triple.equals(subj.replace("ns:", "http://rdf.freebase.com/ns/")))
continue;
if( !triple.startsWith("http://rdf.freebase.com/ns/") )
results.add(triple);
else
results.addAll(this.retrieveNames(triple.replace("http://rdf.freebase.com/ns/", "")));
}
return results;
}
@SuppressWarnings("finally")
public Set<String> executePOQuery(String po){
Set<String> names = new HashSet<String>();
try{
Set<String> result = new HashSet<String>();
String pred = po.split("\t")[0].trim();
String obj = po.split("\t")[1].trim();
for (String triple : this.execute("sparql select * where {?x <" + pred.replace("ns:", "http://rdf.freebase.com/ns/") + "> <"
+ obj.replace("ns:", "http://rdf.freebase.com/ns/") + "> .}")) {
String mid = triple;
result.add(mid);
}
result.remove(obj.replace("ns:", "http://rdf.freebase.com/ns/"));
if( result.size() > 100 )
return names;
for(String mid : result){
if( !mid.startsWith("http://rdf.freebase.com/ns/") ){
names.add("\""+URLDecoder.decode(new String(mid.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"")+"\"");
}
else{
for(String triple : this.execute("sparql select * where {<"+mid+"> <http://rdf.freebase.com/ns/type.object.name> ?z .}")){
names.add("\""+URLDecoder.decode(new String(triple.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"")+"\"");
}
}
}
}catch(Exception e){
}finally{
return names;
}
}
@SuppressWarnings("finally")
public Set<String> executeTriangle(String sp){
Set<String> names = new HashSet<String>();
try{
Set<String> result = new HashSet<String>();
String[] info = sp.split("\t");
String subj = info[0];
String pred_1 = info[1].trim();
String pred_2 = info[2].trim();
for (String triple : this
.execute("sparql select ?y where {?x <" + pred_1.replace("ns:", "http://rdf.freebase.com/ns/") + "> <"
+ subj.replace("ns:", "http://rdf.freebase.com/ns/") + "> . " + "?x <"
+ pred_2.replace("ns:", "http://rdf.freebase.com/ns/") + "> ?y .}")) {
String mid = triple;
result.add(mid);
}
if (result.size() > 100)
return names;
for (String mid : result) {
if (!mid.startsWith("http://rdf.freebase.com/ns/")) {
names.add("\"" + URLDecoder.decode(new String(mid.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"") + "\"");
} else {
for (String triple : this.execute(
"sparql select * where {<" + mid + "> <http://rdf.freebase.com/ns/type.object.name> ?z .}")) {
names.add("\"" + URLDecoder.decode(new String(triple.replace("%", "").getBytes("ISO8859-1")), "utf-8").replace("\"", "\\\"") + "\"");
}
}
}
}catch(Exception e){
}finally{
return names;
}
}
public Set<String> retrieveAnswerType(String sp) throws Exception{
Set<String> types = new HashSet<String>();
String subj = sp.split("\t")[0];
String pred = sp.split("\t")[1].trim();
if( pred.indexOf("..") != -1 ){
String firstPredicate = pred.split("\\.\\.")[0];
String secondPredicate = "ns:"+pred.split("\\.\\.")[1];
for(String triple : this.execute("sparql select ?x where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> <"+firstPredicate.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?x. "
+ "?x <"+secondPredicate.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?y .}"
+ "?y <http://rdf.freebase.com/ns/type.object.type> ?z ." )){
types.add(triple);
}
}
else{
for(String triple : this.execute("sparql select ?y where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> <"+pred.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?x ."
+ "?x <http://rdf.freebase.com/ns/type.object.type> ?y ."
+ "}")){
types.add(triple);
}
}
return types;
}
public Set<String> retrieveRelations(String subj) throws Exception{
Set<String> relations = new HashSet<String>();
for(String triple : this.execute("sparql select ?x ?z where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?x ?y. "
+ "?y ?z ?m .}") ){
triple = triple.replace("http://rdf.freebase.com/ns/", "");
String[] info = triple.split("\t");
relations.add("ns:"+info[0]);
if( !info[1].equals("type.object.name") && !info[1].startsWith("user.") && !info[1].startsWith("base."))
relations.add("ns:"+info[0]+".."+info[1]);
}
return relations;
}
public List<String> retrieveWikiIds(String mid) throws Exception{
List<String> triples = this.execute("sparql select ?x where { <http://rdf.freebase.com/en/"+mid+"> <http://rdf.freebase.com/ns/type.namespace.keys> ?x}");
for(int i = triples.size()-1; i >= 0; i--){
System.err.println(triples.get(i));
}
return triples;
}
public List<String> retrieveNames(String mid){
List<String> triples = this.execute("sparql select ?x where { <http://rdf.freebase.com/ns/"+mid+"> <http://rdf.freebase.com/ns/type.object.name> ?x}");
return triples;
}
public String retrieveDescription(String mid){
List<String> triples = this.execute("sparql select ?x where { <http://rdf.freebase.com/ns/"+mid+"> <http://rdf.freebase.com/ns/common.topic.description> ?x}");
if( triples.size() == 0 )
return "";
return triples.get(0);
}
public Set<String> execute2HopQuery(String subj, String firstPred, String secondPred, String sibling){
Set<String> results = new HashSet<String>();
subj = "ns:"+subj;
firstPred = "ns:"+firstPred;
secondPred = "ns:"+secondPred;
List<String> triples = this.execute("sparql select ?z ?target where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> <" + firstPred.replace("ns:", "http://rdf.freebase.com/ns/") + "> ?x. "
+ "?x <"+secondPred.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?z."
+ "?x ?n ?target .}");
for(int i = 0; i < triples.size(); ){
String triple = triples.get(i);
String[] info = triple.split("\t");
String ans = new String();
String target = new String();
if( info.length != 2 ){
ans = triples.get(i);
target = triples.get(i+1);
i+=2;
}
else{
ans = info[0];
target = info[1];
i++;
}
if( ans.equals(subj.replace("ns:", "http://rdf.freebase.com/ns/")) )
continue;
if( target.equals(sibling) )
results.add(ans);
}
if( results.size() == 0 ){
triples = this.execute("sparql select ?z ?target where {<"+subj.replace("ns:", "http://rdf.freebase.com/ns/")+"> <" + firstPred.replace("ns:", "http://rdf.freebase.com/ns/") + "> ?x."
+ "?x <"+secondPred.replace("ns:", "http://rdf.freebase.com/ns/")+"> ?z. "
+ "?x ?n ?y. "
+ "?y <http://rdf.freebase.com/ns/type.object.name> ?target.}");
}
for(int i = 0; i < triples.size(); ){
String triple = triples.get(i);
String[] info = triple.split("\t");
String ans = new String();
String target = new String();
if( info.length != 2 ){
ans = triples.get(i);
target = triples.get(i+1);
i+=2;
}
else{
ans = info[0];
target = info[1];
i++;
}
if( ans.equals(subj.replace("ns:", "http://rdf.freebase.com/ns/")) )
continue;
if( target.equals(sibling) )
results.add(ans);
}
HashSet<String> names = new HashSet<String>();
for(String result : results){
names.addAll(this.retrieveNames(result.replace("http://rdf.freebase.com/ns/", "")));
}
return names;
}
public static void main(String[] args) {
Virtuoso instance = new Virtuoso();
// String sparql = "sparql PREFIX ns: <http://rdf.freebase.com/ns/> SELECT DISTINCT ?x, ?name WHERE { ns:m.0rmlp ns:location.location.containedby ?x . ?x ns:common.topic.notable_types ns:location.us_county . ?x ns:type.object.name ?name .}";
String sparql = "sparql PREFIX ns: <http://rdf.freebase.com/ns/> SELECT DISTINCT ?x, ?name WHERE { ns:m.04ly1 ns:location.location.time_zones ?x . ?x ns:type.object.name ?name .}";
List<String> answers = instance.execute(sparql);
System.out.println(answers);
}
}